Compendium Specialty Series: Feline Focus

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2008 Feline Retrovirus Management Guidelines* Members of the Advisory Panel ❯❯ Julie Levy, DVM, PhD, DACVIM, Chair ❯❯ Cynda Crawford, DVM, PhD University of Florida

❯❯ Katrin Hartmann, Dr. Med. Vet., Dr. Habil., DECVIN-CA Ludwig Maximilian University Munich | Munich, Germany

❯❯ Regina Hoffmann-Lehmann, Dr. Med. Vet., Dr. Habil, FVH University of Zurich | Zurich, Switzerland

❯❯ Susan Little, DVM, DABVP (Feline Practice)

Winn Feline Foundation | Manasquan, New Jersey

❯❯ Eliza Sundahl, DVM, DABVP (Feline Practice)

F

eLV and FIV are among the most common infectious diseases of cats. Risk factors for infection include male gender, adulthood, and outdoor access, whereas indoor lifestyle and sterilization are associated with reduced infection rates.1–5 The retroviral status of all cats should be known. Cats may require retrovirus testing at different times in their lives. Here are some general principles for retrovirus testing:

A cat with a confirmed-positive test result should be diagnosed as having a retroviral infection—not clinical disease. Diseases in cats infected with FeLV or FIV may not necessarily be the result of the retrovirus infection. Cats infected with FeLV or FIV may live for many years. A decision for euthanasia should never be made solely on the basis of whether the cat is infected. No test is 100% accurate at all times under all conditions. All test results should be interpreted along with the patient’s health and prior likelihood of infection. All positive results should be confirmed by another test method.

While FeLV and FIV can be life-threatening viruses, proper management can give infected cats longer, healthier lives. The following article reflects the recommendations of the AAFP on managing these infections.

KC Cat Clinic | Kansas City, Missouri

❯❯ Vicki Thayer, DVM, DABVP (Feline Practice) Purrfect Practice | Lebanon, Oregon

At a Glance Epidemiology Page 265

Preventing FeLV and FIV Infection Page 265

Limiting Transmission in the Veterinary Practice Page 268

Diagnosing FeLV and FIV Page 269

Managing Positive Cats

About These Guidelines This report represents a consensus of current information compiled by the researchers and practitioners on the panel. These guidelines are based on the best research data, clinical experience and technical judgments available at the time of preparation. While the guidelines are as accurate and comprehensive as possible, they are subject to change should new insights become available from additional research or technological updates. The American Association of Feline Practitioners is a professional organization of practitioners and board-certified specialists who seek to raise the standards of feline medicine and surgery among practitioners.

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* This is an abridged version of the full guidelines (Levy JC, Crawford C, Hartmann K, et al. 2008 American Association of Feline Practitioners’ feline retrovirus management guidelines. J Feline Med Surg 2008;10[3]:300-316) available at catvets.com from the American Association of Feline Practitioners (AAFP). Adapted with permission from AAFP.

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Contributed by

AMERICAN ASSOCIATION OF FELINE PRACTITIONERS

About AAFP

Epidemiology

FeLV Vaccination

The prevalence of FeLV infection has reportedly decreased during the past 20 years, presumably as a result of implementation of widespread testing programs and development of effective vaccines.1,2,6 In contrast, the prevalence of FIV has not changed since the virus was discovered in 1986. In a study of more than 18,000 cats tested in 2004, 2.3% were positive for FeLV and 2.5% were positive for FIV.1 Infection rates for FeLV and FIV (Table 1) varied among subpopulations and sources of cats.

The decision to vaccinate an individual cat against FeLV should be based on the cat’s risk of exposure. Cats that live in an FeLV-negative, indoor environment are at minimal risk. FeLV vaccination is recommended for:

Preventing FeLV and FIV Infection

All kittens because the lifestyles of kittens frequently change after acquisition, and kittens may subsequently be at risk for FeLV exposure Cats that go outdoors Cats that have direct contact with cats of un­known status or in high-turnover situations such as foster homes or other group housing Cats that live with FeLV-positive cats

Vaccines are available for both retroviruses. Both FeLV and FIV vaccines are non-core. Risk assessment of the individual animal should dictate their use. No vaccine is 100% effective, and repeat testing should be performed as warranted.

Because sufficient protection is not induced in all vaccinates, vaccination against FeLV does not diminish the importance of testing cats to identify and isolate those that are viremic. In

The American Association of Feline Practitioners improves the health and well-being of cats by supporting high standards of practice, continuing education, and scientific investigation. Feline Practitioners are veterinary professionals who belong to this association because they are “passionate about the care of cats”! American Association of Feline Practitioners 203 Towne Centre Drive Hillsborough, NJ 08844-4693 phone: 800-874-0498 phone: 908-359-9351 fax: 908-292-1188 e-mail: info@catvets.com Media contact: Valerie Creighton, DVM, DABVP

table 1

Risk Factors for FeLV and FIV Seropositivity in 18,038 Cats Tested at Veterinary Clinics and Animal Shelters in North America1 Number of Cats Tested

Number of Cats With Positive Results for FeLV (%)

Number of Cats With Positive Results for FIV (%)

Animal shelter

8068

124 (1.5)

141 (1.7)

Veterinary clinic

9970

285 (2.9)

305 (3.1)

West

3737

39 (1.0)

72 (1.9)

Factor

Categories

Study site Region

Source

Age Sex

Canada

325

8 (2.5)

10 (3.1)

South

6359

144 (2.3)

183 (2.9)

Northeast

3747

107 (2.9)

79 (2.1)

Midwest

3870

111 (2.9)

102 (2.6)

Clinic (indoors only)

3613

53 (1.5)

32 (0.9)

Clinic (outdoors access)

6357

232 (3.6)

273 (4.3)

Shelter (relinquished pet)

2809

41 (1.5)

38 (1.4)

Shelter (stray)

4550

71 (1.6)

75 (1.6)

Shelter (feral)

709

12 (1.7)

28 (3.9)

Juvenile

9556

131 (1.4)

100 (1.0)

Adult

8482

278 (3.3)

346 (4.1)

Spayed female

2611

45 (1.7)

44 (1.7)

Neutered male

2984

88 (2.9)

127 (4.3)

Sexually intact female

6588

128 (1.9)

82 (1.2)

Sexually intact male Health status

Healthy Sick

5855

148 (2.5)

193 (3.3)

15,312

238 (1.6)

280 (1.8)

2726

171 (6.3)

166 (6.1)

Disclaimer These guidelines are not exclusive. Other techniques and procedures may be available. The AAFP expressly disclaims any warranties or guarantees, express or implied, and shall not be liable for any damages of any kind in connection with the material, information, techniques, or procedures set forth in these guidelines.

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QuickNotes The retroviral status of all cats should be known because the serious health consequences of infection influence patient management both in illness and wellness care.

addition, cats should be tested for FeLV infection before initial vaccination and whenever the possibility exists that they have been exposed to FeLV since they were last tested. Administering FeLV vaccines to cats confirmed to be FeLV infected is of no value.

FIV Vaccination The decision to vaccinate a cat for FIV is complicated. FIV vaccines may be considered for cats with lifestyles that put them at high risk for infection, such as outdoor cats that fight or cats living with FIV-infected cats. Because FIV infection is more often spread by unfriendly exchanges (usually biting), cats in households with a stable social structure are at lower risk for acquiring FIV infection.

Current FIV antibody tests cannot distinguish vaccinated cats from infected cats. Clients should be informed that vaccinated cats will have positive FIV test results, and the decision to vaccinate should be reached only after careful consideration of this implication. If the decision falls in favor of vaccination, cats should test negative immediately before vaccination. A permanently placed identification microchip and collar are recommended for all cats to increase the chance of returning lost cats to their owners. Microchip databases can also record FIV vaccination histories. This information can be used by animal shelters to help assess the significance of positive FIV test results when screening cats before adoption.

General Recommendations for Testing for and Controlling Transmission of FeLV and FIV in Shelters and Breeding Catteries Testing As for pet cats, it is ideal for all cats in shelters and catteries to be tested for FeLV and FIV.* Testing at admission is optional for singly housed cats. Testing is highly recommended for group-housed cats. If not performed before adoption, testing should be recommended to the new owner before exposure to other cats. Testing should be repeated 60 days after the initial test and annually for cats kept in long-term group housing. Each cat should be individually tested. Testing representative kittens in a litter or colony and extrapolating results to other cats in the group is unreliable. Procedures such as pooling mul-

tiple samples for use in a single test reduce test sensitivity and should not be performed. Foster families and adopters should have their own resident cats tested before fostering or adopting a new cat. Testing is optional in feral cat trap– neuter–return programs. Controlling Transmission FeLV vaccination is optional for singly housed cats. FeLV vaccination is highly recommended for all cats housed in groups and for foster cats and permanent residents in foster homes. Cats should test negative before vaccination. In catteries that follow testing guidelines and maintain retrovirus-negative

Box 1

status, vaccination against FeLV and FIV is not necessary. Vaccination is not 100% effective and should never be used in place of a test-and-segregate program. In contrast to feline panleukopenia, herpesvirus, and calicivirus vaccines, the value of a single FeLV vaccine for feral cats has not been determined. Therefore, FeLV vaccination is not recommended for feral cat trap–neuter– return programs if program resources are needed for higher priorities. FIV vaccination is not recommended for use in shelters or feral cats. Strict adherence to universal precautions is required to prevent iatrogenic transmission of retroviruses in the shelter environment via contaminated equipment and secretions.

*Currently, no test can distinguish FIV antibodies induced by infection from those induced by vaccination. Therefore, shelters have the difficult task of determining the true infection status of stray cats that are admitted without medical histories and that test positive for FIV antibodies. If the cat is microchipped, the history of FIV vaccination may be recorded in an accessible database. However, even if cats are known to have been vaccinated against FIV, determining whether they are also infected is not usually possible. This is a challenge for shelters for which no solution currently exists.

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Federal (U.S.A.) law restricts this drug to use by or on the order of a licensed veterinarian. Children should not contact application site for twenty-four (24) hours. See Page 448 for Product Information Summary

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Limiting Transmission in the Veterinary Practice

FeLV and FIV Diseases

Retroviruses are unstable outside their host animals and can be quickly inactivated by detergents and routine disinfectants.7–11 Simple precautions and routine cleaning procedures prevent transmission of these agents in veterinary hospitals. As a guide:

QuickNotes Retroviruses can be quickly inactivated by detergents and routine disinfectants.

Although many FeLV-/FIV-infected cats experience prolonged survival, retroviral infections can be associated with: nemia A econdary and opportunistic infections S Neoplasia Chronic inflammatory conditions Ocular disorders Hematologic disorders

All infected patients should be housed in individual cages when hospitalized and not in isolation/contagious wards where they may be exposed to infectious agents. Hospital staff should wash their hands between patients and after cleaning cages. Because FeLV and FIV can be transmitted in blood transfusions, donors should be tested before donating. A real-time polymerase chain reaction (PCR) test for FeLV is recommended for blood donors because proviral elements in seronegative cats with regressive FeLV in­fection may cause infection in transfusion recipients. FIGURE 1 2

Box 2

Specific diseases associated with very high rate of infection: Cutaneous abscesses (FeLV: 8.8%, FIV: 12.7%)12 Oral inflammation (FeLV: 7.3%, FIV: 7.9%)a Bellows J, Lachtara JL. Feline retroviruses and oral disease [unpublished]. Reported in: Veterinary Medicine, “Spotlight on Research”; 2006. a

FeLV Antigen test

FeLV antigen positive

FeLV antigen negative

All positive results should be confirmed.

Negative screening test results are highly reliable. However, if results are negative but recent infection cannot be ruled out, testing should be repeated a minimum of 30 days after the last potential exposure.

Retest immediately with IFA.

IFA test

FeLV IFA negative

FeLV IFA positive Consider FeLV infected and start appropriate management program.

Discordant results may be due to the stage of infection, the variability of host responses, or technical problems with testing. It is not usually possible to determine the true FeLV infection status of cats with persistently discordant test results. If resolving is desired, retest in 60 days using antigen and IFA.

FeLV test interpretation algorithm—all cats. IFA = immunofluorescence assay

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Dental and surgical instruments, endotracheal tubes, and other items potentially contaminated with body fluids should be thoroughly cleaned and sterilized between uses. Fluid lines, multidose medication containers, and food can become contaminated with body fluids (especially blood or saliva) and should not be shared among patients. Recommendations on testing for and controlling transmission of FeLV and FIV in shelters and catteries are listed in box 1.

Diagnosing FeLV and FIV The retroviral status of all cats should be known because the serious health consequences of infection influence patient management both in illness and wellness care. Failure to identify infected cats may lead to inadvertent exposure and transmission to uninfected cats. Misdiagnosis of infection in uninfected cats may lead to inappropriate changes in lifestyle or even euthanasia. FIGURE 2

Cats should be tested when they are: Sick, regardless of age, despite previous negative test results or previous vaccination. FeLV and FIV are associated with a wide variety of health disorders4,5 (Box 2). Identification of retroviral infection as a complicating factor can assist in the development of optimal management plans. About to be adopted or brought into a new household, regardless of age. Even if no other cats are present in the household, testing will protect future cats that may join the family as well as neighborhood cats, should the pet escape or be allowed outside. At risk of exposure, even if their most recent test was negative. As an example, a 2008 study12 showed that more than 19% of cats with cutaneous abscesses were FIV or FeLV positive at the time of presentation. Because of delay in seroconversion after initial infection, these cats should also be retested (a

FIV Antibody test

FIV antibody positive

Negative screening test results are highly reliable. However, if results are negative but recent infection cannot be ruled out, testing should be repeated a minimum of 60 days after the last potential exposure.

Retest with another antibody test.

> 6 Months of age

Retest at 60-day intervals FIV antibody positive If positive after kitten reaches 6 months of age, consider FIV infected.

ELISA and other immunochromatographic tests are the preferred screening tests for FeLV and FIV.

FIV antibody negative

All positive results should be confirmed. Cats vaccinated with a whole-virus vaccine will test antibody positive.

< 6 Months of age

QuickNotes

Retest immediately with different test

FIV antibody negative If negative at any interval, consider free of infection and begin a wellness program.

FIV antibody positive

FIV antibody negative

Consider FIV infected and continue appropriate management program.

Consider free of infection and begin a wellness program.

Note: False-positive results will exist in vaccinated cats.

FIV test interpretation algorithm—all cats. CompendiumVet.com | June 2009 | Compendium: Continuing Education for VeterinariansŽ

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minimum of 30 days after the last potential FeLV exposure and 60 days after potential FIV exposure). Of “unknown” viral status. Infected cats can remain asymptomatic for years, during which time they may serve as hidden sources of infection to other cats in the household. About to be vaccinated against FeLV or FIV. These vaccines should not be administered to cats that are already infected. Vaccination does not affect the carrier state, the capacity to infect other cats, or the development of disease in cats with preexisting infection.

from a different manufacturer.18,19 Western blot tests have been the recommended confirmation tests in the past, but they were found to be less sensitive and specific than in-clinic screening tests in one study.17 Vaccination of cats against FIV induces antiFIV antibodies that cannot be distinguished from natural infection. These antibodies persist for at least 1 year and can be transferred in colostrum to kittens. While PCR assays may help distinguish cats infected with FIV from cats vaccinated against FIV, one study found marked variability in diagnostic accuracy among commercial laboratories.20

Diagnosis of FeLV

QuickNotes Both FeLV-infected and FIV-infected cats can live for many years.

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*** Soluble-antigen tests are preferred for initial screening (Figure 1). These include ELISA and Negative results for either FeLV or FIV other immunochromatographic tests. are much more reliable than positive results While screening tests detect the presence of because of the low prevalence of infecfree antigen in the circulating blood, the immu- tion in most cat populations. Positive test nofluorescence assay (IFA) tests for the presence results should be confirmed, especially in of antigen within infected white blood cells and asymptomatic and low-risk cats. No test is platelets. Positive results from tests that detect 100% accurate all the time, under all confree antigen may be reflective of the transient ditions. In cat populations with a low period of antigenemia associated with regres- prevalence (e.g., <1%), more than half of the sive infections. Positive results from tests that cats that test positive are likely to be uninfected.21 detect cell-associated antigen, such as the IFA, Kittens may be tested for FeLV and FIV at are likely to be reflective of progressive infec- any age. Most kittens test negative, indicattions. Tests that use saliva and tears yield an ing no infection. Antibody tests for FIV can unacceptably high percentage of inaccurate detect antibodies passed in colostrum from an infected or vaccinated mother, which can results, and their use is not recommended.13 Although there are no published assessments be mistaken for infection in the kitten. Kittens of diagnostic accuracy of PCR testing for FeLV, that test positive for FIV antibodies should the test is offered by a number of commercial be retested every 60 days up to 6 months laboratories. Recent studies14,15 using real-time of age. If the kitten becomes seronegative, it PCR have shown that 5% to 10% of cats with most likely is not infected. If results of tests negative results on soluble antigen tests were performed after 6 months of age are still conpositive for FeLV provirus by PCR (regressive firmed positive, these kittens should be coninfection). sidered infected. FeLV vaccinations will not induce positive Diagnosis of FIV test results. FIV produces a persistent, lifelong infection, FIV vaccinations will induce positive test so detection of antibodies in peripheral blood results. has been judged sufficient for routine diagnostic screening if the cat has not been previously Managing Positive Cats vaccinated against FIV and has not acquired Both FeLV-infected and FIV-infected cats can live for many years and may succumb at older FIV antibodies in colostrum16,17 (Figure 2). ELISA and other immunochromatographic ages to causes unrelated to their retrovirus tests are the preferred screening tests. Confir­ infections. In recent studies,22 the median surmation of positive screening tests should include vival after diagnosis of FeLV-infected cats was a different method or at least an antibody test 2.4 years; for FIV-infected cats, it was 4.9 years.

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TREATMENT EA ATTMENT AI AID D FOR F OR FeLV eLLV / FIV FI FV INFECTIONS FECTION NS LTCI

LYMPHOCYTE T-CELL IMMUNOMODULATO NOMODUL ATOR R

Approved Treatment Aid for: f or : FeLV and/or FIV infections ections ti

Including Associated Symptoms of: Oppor tunistic infection ction Lymphopenia Anemia Granulocytopenia Thrombocytopenia

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Thus, a decision for treatment or for euthanasia should never be based solely on the presence of a retrovirus infection.

Infected queens should not be bred and should be spayed if their condition is sufficiently stable to permit them to undergo surgery.

Managing Healthy Positive Cats Examinations should be performed at least twice a year. At each visit: Update medical history. Monitor for any signs of weight loss. Perform a thorough physical examination; pay close attention to the lymph nodes, eyes, and oral cavity. Conduct a complete blood count, biochemical analysis, urinalysis, and fecal examination at least once a year. FeLV-positive cats may need a complete blood count twice a year. Spay or neuter intact cats. Control internal and external parasites. Vaccinate as lifestyle indicates. Most retrovirusinfected cats mount adequate immune responses when vaccinated, and there is no need to modify standard vaccination intervals.23 There is controversy about the use of inactivated versus modified-live vaccines. Cur­rent recommendations are to use inactivated vaccine products due to the theoretical risk of a modified-live product regaining its pathogenicity in cats with compromised immune systems.

Managing Clinically Ill Positive Cats Prompt and accurate diagnosis is essential to allow early therapeutic intervention and a successful treatment outcome. Therefore, intensive diagnostic testing should proceed early in the course of illness for infected cats. Many cats infected with FeLV or FIV respond as well as their uninfected counterparts to appropriate medications and treatment strategies, although a longer or more aggressive course of treatment may be needed. Few attempts have been made to evaluate antiviral drugs, immunomodulators, or alternative therapies in large controlled studies of naturally infected cats. To date, no treatment has been shown to reverse well-established retrovirus infection in cats. Clients with a healthy or ill retroviruspositive cat may be frightened by the initial diagnosis. It is important to alleviate these fears when appropriate and offer encouraging advice on the proper care and management of the cat (Box 3). Box 3

Advice for Owners of Infected Cats Limiting Transmission at Home Confine—Infected cats should be confined indoors so they do not pose a risk of infection to other cats and so they are protected against infectious hazards in the environment. Isolate—The best method of preventing spread to other cats in the household is to isolate the infected cat from interacting with its housemates. Isolation in a separate room is recommended, but a simple screen or chain-link barrier is adequate. Generally, FeLV transmission is low in households with stable social structures where housemates do not fight, but FeLV can still be transmitted via friendly interactions.

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Don’t Introduce—If separation is not possible,

no new cats should be introduced in the household to reduce the risk of territorial aggression.

If owners choose not to separate retrovirusinfected housemates from their other cats, the uninfected cats should be considered for vaccination. Vaccinated cats should be isolated from infected cats for at least 2 months after the vaccine series. Managing Positive Cats Watch closely for behavioral changes in the cat. Feed a nutritionally balanced diet. Avoid raw diets because of the risk of food-borne bacterial and parasitic infections.

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References

1. Levy JK, Scott HM, Lachtara JL, Crawford PC. Seroprevalence of feline leukemia virus and feline immunodeficiency virus infection among cats in North America and risk factors for seropositivity. JAVMA 2006;228:371376. 2. O’Connor TP Jr, Tonelli QJ, Scarlett JM. Report of the National FeLV/FIV Awareness Project. JAVMA 1991;199:1348-1353. 3. Levy JK, Crawford PC. Feline leukemia virus. In: Ettinger SJ, Feldman EC, eds. Textbook of Veterinary Internal Medicine. 6th ed. Philadelphia: WB Saunders; 2005:653-659. 4. Hoover EA, Mullins JI. Feline leukemia virus infection and diseases. JAVMA 1991;199:1287-1297. 5. Levy JK. Feline immunodeficiency virus update. In: Bonagura J, ed. Current Veterinary Therapy XIII. Philadelphia: WB Saunders; 2000:284-288. 6. Moore GE, Ward MP, Dhariwal J, Al E. Use of a primary care veterinary medical database for surveillance of syndromes and diseases in dogs and cats. J Vet Intern Med 2004;18:386. 7. Francis DP, Essex M, Gayzagian D. Feline leukemia virus: survival under home and laboratory conditions. J Clin Microbiol 1979;9:154-156. 8. van Engelenburg FA, Terpstra FG, Schuitemaker H, Moorer WR. The virucidal spectrum of a high concentration alcohol mixture. J Hosp Infect 2002;51:121-125. 9. Moorer WR. Antiviral activity of alcohol for surface disinfection. Int J Dent Hyg 2003;1:138-142. 10. Kramer A, Schwebke I, Kampf G. How long do nosocomial pathogens persist on inanimate surfaces? A systematic review. BMC Infect Dis 2006;6:130. 11. Terpstra FG, Van Den Blink AE, Bos LM, et al. Resistance of surface-dried virus to common disinfection procedures. J Hosp Infect 2007;66:332-338. 12. Goldkamp CE, Levy JK, Edinboro CH, Lachtara JL. Seroprevalences of feline leukemia virus and feline immunodeficiency virus in cats with abscesses or bite wounds and rate of veterinarian compliance with current guidelines for retrovi-

rus testing. JAVMA 2008;232:1152-1158. 13. Panel report on the colloquium on feline leukemia virus/feline immunodeficiency virus: tests and vaccination. JAVMA 1991;199:1273-1277. 14. Hofmann-Lehmann R, Huder JB, Gruber S, et al. Feline leukemia provirus load during the course of experimental infection and in naturally infected cats. J Gen Virol 2001;82:1589-1596. 15. Gomes-Keller MA, Go¨nczi E, Tandon R, et al. Detection of feline leukemia virus RNA in saliva from naturally infected cats and correlation of PCR results with those of current diagnostic methods. J Clin Microbiol 2006;44:916-922. 16. Hartmann K. Feline immunodeficiency virus infection: an overview. Vet J 1998;155:123-137. 17. Levy JK, Crawford PC, Slater MR. Effect of vaccination against feline immunodeficiency virus on results of serologic testing in cats. JAVMA 2004;225:1558-1561. 18. Barr MC. FIV, FeLV, and FIPV: interpretation and misinterpretation of serological test results. Semin Vet Med Surg Small Anim 1996;11:144-153. 19. Hartmann K, Werner RM, Egberink H, Jarrett O. Comparison of six inhouse tests for the rapid diagnosis of feline immunodeficiency and feline leukemia virus infections. Vet Rec 2001;149:317-320. 20. Bienzle D, Reggeti F, Wen X, et al. The variability of serological and molecular diagnosis of feline immunodeficiency virus infection. Can Vet J 2004;45:753-757. 21. Jacobson RH. How well do serodiagnostic tests predict the infection or disease status of cats? JAVMA 1991;199:1343-1347. 22. Levy JK, Lorentzen L, Shields J, Lewis H. Long-term outcome of cats with natural FeLV and FIV infection. In: 8th Int Feline Retrovirus Res Symp 2006. 23. Richards JR, Elston TH, Ford RB, et al. The 2006 American Association of Feline Practitioners Feline Vaccine Advisory Panel Report. JAVMA 2006;229:1405-1441.

OCTOBER 12–15, 2009 Atlantic City Convention Center

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• We provide over 330 hours of stimulating education in an environment that emphasizes the entire veterinary team • 23 RACE approved Continuing Education credits • Wet labs for veterinarians: Ultrasound, Rigid Endoscopy, Ear Therapeutics, Stifle Procedures, Tibial Tuberosity Advancement, and more! • Wet labs for technicians: Animal Behavior, Canine CPR, Dental Radiography, Clinical Chemistry, Instrument Care, and more! Wet Lab Space is Limited! Be sure to register early!

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2008 AAFP Senior Care Guidelines* Panelists ❯❯ Jeanne Pittari, DVM, DABVP (Feline Practice),

Co-Chair Memorial Cat Hospital, Houston, Texas ❯❯ Ilona Rodan, DVM, DABVP (Feline Practice),

Co-Chair Cat Care Clinic, Madison, Wisconsin ❯❯ Gerard Beekman, DVM Coastal Cats Feline Health Care, York, Maine ❯❯ Danièlle Gunn-Moore, BVM&S, PhD, MACVSc,

MRCVS, RCVS Specialist in Feline Medicine University of Edinburgh, Scotland ❯❯ David Polzin, DVM, PhD, DACVIM-SAIM University of Minnesota ❯❯ Joseph Taboada, DVM, DACVIM-SAIM Louisiana State University ❯❯ Helen Tuzio, DVM, DABVP (Feline Practice) Catnap Feline Veterinary Relief Services, Rego Park, New York ❯❯ Debra Zoran, DVM, PhD, DACVIM-SAIM Texas A&M University

At a Glance The Senior Cat Wellness Visit Page 402

Minimum Database in Senior Cats Page 403

Monitoring and Managing Disease Page 404

Quality of Life

C

ats are the most popular pet in the United States and much of northern Europe.1 Although 78% of owners consider their cats to be family members,2 many cats, particularly seniors, do not receive appropriate preventive care.3,4 With good care, many cats live into their late teens and some into their twenties; the percentage of older cats is increasing.5,6 Older cats can be classified as mature or middle-aged (7 to 10 years), senior (11 to 14 years), or geriatric (15+ years). In this article, as elsewhere, the word senior is used as a broad category for all older cats, unless otherwise noted. The goals of the American Association of Feline Practitioners (AAFP) Senior Care Guidelines are to assist veterinarians to deliver consistent high-quality care to senior cats, promote feline longevity, and improve the quality of life of senior cats.

The Senior Cat Wellness Visit Use open-ended questions (e.g., “What behavior changes have you noticed in the last few weeks?”) to obtain a comprehensive medical and behavioral history. Issues identified with such questions can raise the index of suspicion for early disease. The frequency of behavior problems increases with age. Perform a thorough physical examination to enable detection of problems that may not be obvious to owners or discovered with laboratory testing. Make weight and body condition score (BCS) comparisons at each visit.

About These Guidelines This report represents a consensus of current information compiled by the researchers and practitioners on the panel. These guidelines are based on the best research data, clinical experience, and technical judgments available at the time of preparation. While the guidelines are as accurate and comprehensive as possible, they are subject to change should new insights become available from additional research or technological updates. The American Association of Feline Practitioners is a professional organization of practitioners and board-certified specialists who seek to raise the standards of feline medicine and surgery among practitioners.

Page 406

*This is an abbreviated version of the senior care guidelines, the full text of which can be found at catvets. com/professionals/guidelines/publications/?Id=398 and in the September 2009 issue of the Journal of Feline Medicine and Surgery Clinical Practice. The guidelines are in memory of the late Dr. James R. Richards, who coauthored the initial senior guidelines in 1998 and who loved to say, “Cats are masters at hiding illness.”

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Compendium grants permission to reproduce this article for educational purposes. A downloadable version of this article is available on CompendiumVet.com.


Contributed by

AMERICAN ASSOCIATION OF

FELINE PRACTITIONERS

About AAFP

Examine apparently healthy senior cats every 6 months. More frequent evaluations may be needed once evidence of an age-related disease process is discovered. Obtain a minimum database (MDB; TABLE 1) at least annually starting at age 7 to 10 years. Increase the frequency of the MDB as a cat ages. Rely on clinical judgment and discussions with the owner to determine the specific age and frequency of testing for each individual cat. Trends in the MDB can be significant, allowing detection of disease earlier than interpretation of a single sample.

Interpretation of the Urinalysis Interpretation of the urinalysis, particularly the urine specific gravity and protein, is of particular importance in senior cats. Assess proteinuria in the absence of urinary tract infection or gross hematuria. Dipstick protein measurement is inaccurate; the microalbuminuria test or urine protein:creatinine (UPC) ratio may be indicated for confirmation of proteinuria when the dipstick is positive or when the dipstick is negative and the cat has a disease known to promote proteinuria. If the urine specific gravity is <1.035, repeat the measurement on a subsequent sample to evaluate persistence. Conduct urine culture and sensitivity testing in patients with chronic kidney disease (CKD), diabetes mellitus, and hyperthyroidism. Bacterial infection can be present in the absence of an inflammatory sediment, particu-

larly in patients with these conditions,7 or when the urine is sufficiently dilute to potentially cause misinterpretation of the urine sediment.8

Blood Pressure Monitoring and Hypertension Measure blood pressure at least annually in cats in the senior and geriatric age groups. Some also recommend routine blood pressure monitoring in mature cats to provide baseline measurements for future comparison. ❯ Most hypertensive cats have an identifiable cause for their elevated blood pressure, but idiopathic increases in blood pressure may occur in a substantial subpopulation of older cats.9 ❯ Obtaining an accurate blood pressure requires a consistent approach with attention to detail.10 Measure blood pressure with the owner present in a quiet room. Allowing the cat to acclimate to the room for 5 to 10 minutes can decrease anxiety-associated hypertension by up to 20 mm Hg.

The American Association of Feline Practitioners improves the health and well-being of cats by supporting high standards of practice, continuing education, and scientific investigation. Feline practitioners are veterinary professionals who belong to this association because they are “passionate about the care of cats”! American Association of Feline Practitioners 203 Towne Centre Drive Hillsborough, NJ 08844-4693 phone: 800-874-0498 phone: 908-359-9351 fax: 908-292-1188 e-mail: info@catvets.com Media contact: Valerie Creighton, DVM, DABVP

Nutrition and Body Condition Individualize diet recommendations depending on the BCS. Increase water intake by offering canned food and multiple water dishes. Feeding small meals frequently increases nutrient availability. Measure serum cobalamin (vitamin B12) concentration in any cat with weight loss, diarrhea, or poor appetite that may have gastrointestinal disease. Deficiencies in essential B vitamins can occur with poor intake or intestinal disease.

TABLE 1

Minimum Database in Senior Cats Mature Cats (age 7–10 years)

Test/Panel

Senior/Geriatric Cats (age >10 years)

Complete blood count (hematocrit, red blood cell count, white blood cell count and differential, cytology, platelets)

All patients

All patients

Chemistry screen (total protein, albumin, globulin, ALP, ALT, glucose, blood urea nitrogen, creatinine, potassium, phosphorus, sodium, calcium)

All patients

All patients

Urinalysis (specific gravity, sediment, glucose, ketones, bilirubin, protein)

All patients

All patients

Thyroxine

Depends on patient

All patients

Blood pressure

Depends on patient

All patients

Disclaimer These guidelines are not exclusive. Other techniques and procedures may be available. The AAFP expressly disclaims any warranties or guarantees, express or implied, and shall not be liable for any damages of any kind in connection with the material, information, techniques, or procedures set forth in these guidelines.

ALP = alkaline phosphatase, ALT = alanine aminotransferase

CompendiumVet.com | September 2009 | Compendium: Continuing Education for Veterinarians®

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Design or maintain a weight loss plan for obese cats. Obesity is a metabolic disease with hormonal, metabolic, and inflammatory changes; it is a risk factor for diabetes, osteoarthritis, respiratory distress, lower urinary tract diseases, and early mortality.11 When possible, identify and correct the underlying health problem in cats with unexplained weight loss. Cats in the senior and geriatric age groups often become underweight, resulting in a low BCS.

Dental Care

QuickNotes With good care, many cats live into their late teens and some into their twenties.

404

Interpret free T4 in conjunction with total T4 and clinical signs in cats with normal total T4 and suspected of having hyperthyroidism. The free T4 level can be elevated in cats with nonthyroidal illness.17 Monitor affected cats for kidney disease and hypertension. ❯ Hypertension may persist or develop after treatment. ❯ Even cats with a urine specific gravity >1.035 may have kidney disease that is unmasked after treatment of hyperthyroidism.18

Oral cavity disease is an often-overlooked Diabetes Mellitus cause of morbidity in older cats and can con- Although most cats are insulin dependent at tribute to a general decline in attitude and the time of diagnosis, early glycemic control overall health.12 Age should not exclude the may lead to clinical remission. Of particular treatment of dental disease. importance for senior cats is the effect of concurrent disease, such as chronic pancreatitis, Anesthesia on their health status. Provide intravenous fluids and thermal support; monitor blood pressure and body Inflammatory Bowel Disease and temperature. Older cats require particu- Associated Disease larly attentive care and monitoring to prevent Inflammatory bowel disease, pancreatitis, and cholangiohepatitis may occur separately or together. hypoxia, hypotension, and hypothermia. Attend to comfort and handle gently, parRule out disorders causing digestion/ ticularly for cats with osteoarthritis or muscle absorption problems in euthyroid, nondiawasting. betic cats with unexplained weight loss, vomiting, diarrhea, and increased appetite and thirst. Monitoring and Managing Disease Include measurement of feline pancreatic Chronic Kidney Disease lipase immunoreactivity (fPLI), feline trypsinStage and manage CKD patients using the like immunoreactivity (fTLI), cobalamin International Renal Interest Society (IRIS) (vitamin B ), and folate concentration in the 12 guidelines.13 The IRIS stage is assigned based evaluation.19–22 on the serum creatinine concentration, UPC ratio, and blood pressure. Cancer Monitor blood pressure. CKD is the leading Weight loss in the absence of other identifiable cause of secondary hypertension. causes is a common sign of cancer. Pursuing Evaluate for proteinuria. A UPC ratio >0.4 a diagnosis before the cat’s body condition warrants consideration of treatment. deteriorates may affect the outcome.23 Critical Recommend feeding a “renal” prescription components of cancer therapy include pain diet. Use of such diets has been shown to management, antinausea medication, and nutrireduce uremic episodes, decrease phospho- tional support. rus retention, prevent muscle wasting, and Osteoarthritis increase survival times.14–16 Osteoarthritis is a common but underrecognized condition in senior cats. Signs are often Hyperthyroidism The total thyroxine (T4) level is the appropri- subtle behavioral and lifestyle changes that ate screening test. However, the total T4 level are mistaken for “old age.”24 Management is may be equivocal or normal in cats with a ideally holistic in scope, attending to both the concurrent illness.17 cat and its environment.25

Compendium: Continuing Education for Veterinarians® | September 2009 | CompendiumVet.com


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BRIEF SUMMARY (For Full Prescribing Information, see package insert.) CAUTION: Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. DESCRIPTION: VETORYL is an orally active synthetic steroid analogue that blocks production of hormones produced in the adrenal cortex of dogs. INDICATIONS: VETORYL Capsules are indicatedfor the treatment of pituitary-dependent hyperadrenocorticism in dogs. VETORYL Capsules are indicated for the treatment of hyperadrenocorticism due to adrenocortical tumor in dogs. CONTRAINDICATIONS: The use of VETORYL Capsules is contraindicated in dogs that have demonstrated hypersensitivity to trilostane. Do not use VETORYL Capsules in animals with primary hepatic disease or renal insufficiency. Do not use in pregnant dogs. Studies conducted with trilostane in laboratory animals have shown teratogenic effects and early pregnancy loss. WARNINGS: In case of overdosage, symptomatic treatment of hypoadrenocorticism with corticosteroids, mineralocorticoids and intravenous fluids may be required. Angiotensinconverting enzyme (ACE) inhibitors should be used with caution with VETORYL Capsules, as both drugs have aldosterone-lowering effects which may be additive, impairing the patient’s ability to maintain normal electrolytes, blood volume and renal perfusion. Potassium-sparing diuretics (e.g., spironolactone) should not be used with VETORYL Capsules as both drugs have the potential to inhibit aldosterone, increasing the likelihood of hyperkalemia. HUMAN WARNINGS: Keep out of reach of children. Not for human use. Wash hands after use. Do not empty capsule contents and do not attempt to divide the capsules. Do not handle the capsules if pregnant or if trying to conceive. Trilostane is associated with teratogenic effects and early pregnancy loss in laboratory animals. In the event of accidental ingestion/overdose, seek medical advice immediately and take the labeled container with you. PRECAUTIONS: Hypoadrenocorticism can develop at any dose of VETORYL Capsules. A small percentage of dogs may develop corticosteroid withdrawal syndrome within 10 days of starting treatment. Mitotane (o,p’-DDD) treatment will reduce adrenal function. Experience in foreign markets suggests that when mitotane therapy is stopped, an interval of at least one month should elapse before the introduction of VETORYL Capsules. The use of VETORYL Capsules will not affect the adrenal tumor itself. Adrenalectomy should be considered as an option for cases that are good surgical candidates. ADVERSE REACTIONS: The most common adverse reactions reported are poor/reduced appetite, vomiting, lethargy/dullness, diarrhea, and weakness. Occasionally, more serious reactions including severe depression, hemorrhagic diarrhea, collapse, hypoadrenocortical crisis, or adrenal necrosis/rupture may occur, and may result in death.

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Cognitive Disorders Cognitive changes may result from systemic illness, organic brain disease, true behavioral problems, or cognitive dysfunction syndrome, a neurodegenerative disorder. Rule out all medical illnesses to diagnose a primary cognitive disorder.

Complex Disease Management

comes the responsibility to control pain and distress, assess quality of life, and provide guidance to the owner in end-of-life decisions. The veterinarian must act as a patient advocate when counseling clients about decisions regarding use or continuation of treatment.26 Hospice care patients and their owners benefit from examination every 2 to 4 weeks or as deemed necessary to assess comfort, quality of life, and quality of the relationship. Quality-of-life scales can aid tremendously in end-of-life decision making.

Search for additional disease processes when expected therapeutic results are not obtained. The likelihood of developing more than one disease increases with age. Be aware of issues surrounding Acknowledgments: The American multiple diseases in senior cats: ❯ Diagnosing one disease while Association of Feline missing another, or assuming a sin- Practitioners wishes to gle disease is severe when signs are thank Nestlé Purina, Merial due to multiple diseases (e.g., con- Ltd., IDEXX Laboratocurrent hyperthyroidism and CKD), ries, Inc., Nutramax Laboratories, Inc., is common. ❯ Treatment of some diseases may and Abbott Laboaffect concurrent diseases (e.g., hyper- ratories for their support of these thyroidism and diabetes mellitus).

guidelines.

Quality of Life Hand in hand with the management of chronic illness in senior patients

References 1. American Veterinary Medical Association. U.S. Pet Ownership and Demographic Sourcebook. Schaumburg, IL: American Veterinary Medical Association; 2007. 2. Pew Research Center Publications. Gauging family intimacy: dogs edge cats (dads trail both). March 7, 2006. Accessed July 2009 at http://pewresearch.org/ pubs/303/gauging-familyintimacy. 3. Cohen SP. Can pets function as family members? Western J Nurs Res 2002;24(6):621-638. 4. Adams CL, Bonnett BN, Meek AH. Predictors of owner response to companion animal death in 177 clients from 14 practices in Ontario. JAVMA 2000;217(9):1303-1309. 5. Broussard JD, Peterson ME, Fox PR. Changes in clinical and laboratory findings in cats with hyperthyroidism from 1983 to 1993. JAVMA 1995;206(3):302305. 6. Wolf A. Proceedings of the BSAVA Pedigree Pet Foods Lecture Tour. 2005. 7. Mayer-Roenne BM, Goldstein RE, Erb HN. Urinary tract infections in cats with hyperthyroidism, diabe-

406

tes mellitus, and chronic kidney disease. J Feline Med Surg 2007;9(2):124-132. 8. Chew J, DiBartola S. Recent concepts in feline lower urinary tract disease. Vet Clin North Am Small Anim Pract 2005;35:147-170. 9. Maggio F, DeFrancesco TC, Atkins CE, et al. Ocular lesions associated with systemic hypertension in cats: 69 cases (1985-1998). JAVMA 2000;217(5):695-702. 10. Brown S, Atkins C, Bagley R, et al. Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats. ACVIM Consensus Statement. J Vet Intern Med 2007;21(3):542-558. 11. Lund EM, Armstrong PJ, Kirk CA, Klausner JS. Prevalence and risk factors for obesity in adult cats from private US veterinary practices. J Applied Res Vet Med 2005;3(2):88-96. 12. Richards J, Rodan I, Beekman G, et al. AAFP Senior Care Guidelines for Cats. 1998. Accessed December 2008 at www.catvets.com. 13. International Renal Interest Society (IRIS) Web site. Accessed July 2009 at www.iris-kidney.com. 14. Ross J, Osborne C, Kirk C, et al. Clinical evalua-

Compendium: Continuing Education for Veterinarians® | September 2009 | CompendiumVet.com


tion of dietary modification for treatment of spontaneous chronic kidney disease in cats. JAVMA 2006;229:949-957. 15. Plantinga EA, Everts H, Kastelein A, Beynen AC. Retrospective study of the survival of cats with acquired chronic renal insufficiency offered different commercial diets. Vet Rec 2005;157:185-187. 16. Elliott J, Rawlings JM, Markwell PJ, Barber PJ. Survival of cats with naturally occurring chronic renal failure: effect of dietary management. J Small Anim Pract 2000;41:235-242. 17. Peterson ME, Melián C, Nichols R. Measurement of serum concentrations of free thyroxine, total thyroxine, and total triiodothyronine in cats with hyperthyroidism and cats with nonthyroidal disease. JAVMA 2001;218(4):529-536. 18. Riensche MR, Graves TK, Schaeffer DJ. An investigation of predictors of renal insufficiency following treatment of hyperthyroidism in cats. J Feline Med Surg 2008;10(2):160-166. 19. Simpson KW, Fyfe J, Cornetta A, et al. Subnormal concentrations of serum cobalamin (vitamin B12) in cats with gastrointestinal disease. J Vet Intern Med 2001;15:26-32. 20. Forman A, Marks SL, de Cock HEV, et al. Evaluation of serum feline pancreatic lipase immunoreactivity and helical computed to-

mography versus conventional testing for the diagnosis of feline pancreatitis. J Vet Intern Med 2004;18:807-815. 21. Steiner JM, Williams DA. Serum feline trypsin-like immunoreactivity in cats with exocrine pancreatic insufficiency. J Vet Intern Med 2000;14:627-629. 22. Parent C, Washabau RJ, Williams DA. Serum trypsin-like immunoreactivity, amylase and lipase in the diagnosis of feline acute pancreatitis [abstract]. J Vet Intern Med 1995;9:194. 23. Baez JL, Michel KE, Sorenmo K, Shofer FS. A prospective investigation of the prevalence and prognostic significance of weight loss and changes in body condition in feline cancer patients. J Feline Med Surg 2007;9:411-417. 24. Boehringer Ingelheim. New survey highlights behavioural changes are key to identifying arthritis in cats. UK Vet 2007;12(6): 26-27. 25. Godfrey DR. Osteoarthritis in cats: a retrospective radiological study. J Small Anim Pract 2005;46:425-429. 26. Rollin BE. Ethical issues in geriatric feline medicine. J Feline Med Surg 2007;9:326-334.

QuickNotes The likelihood of developing more than one disease increases with age.

Research Recap Selected abstract from Veterinary Therapeutics

Prevalence of Intestinal Parasites in Companion Animals in Ontario and Quebec, Canada, during the Winter Months* Blagburn BL, Schenker R, Gagné F, Drake J. Vet Ther 2008;9(3):169-175. Veterinarians in Ontario and Quebec, Canada, typically prescribe monthly heartworm prophylactic and anthelmintic medications for use during the warm months of the year. In many patients, the use of dewormers is discontinued during the winter because of the perception that intestinal parasite infections and shedding of nematode eggs are unlikely when the weather is cold and the ground is frozen or covered with snow. This study

TO LEARN MORE

examined fecal samples obtained from 96 shelter dogs and cats during the winter in Ontario and Quebec. Intestinal parasites were identified in 34% of submitted samples. These findings support the recommendation that veterinarians should advise pet owners to continue administration of broad-spectrum parasiticides to companion animals during the winter months.

F From th the Fall 2008 issue

For more Veterinary Therapeutics abstracts, visit the archives at

VeterinaryTherapeutics.com

*This research was sponsored by Novartis Animal Health/Novartis Santé Animale Canada, Mississauga, Ontario, Canada.

CompendiumVet.com | September 2009 | Compendium: Continuing Education for Veterinarians®

407


Update on Feline Upper Respiratory Diseases: Introduction and Diagnostics

Abstract: Clinical signs of upper respiratory disease are com-

❯❯ Jessica Quimby, DVM, DACVIMa ❯❯ Michael R. Lappin, DVM, PhD, DACVIM Colorado State University

Relatively common causes of sneezing or nasal discharge in cats that primarily involve the nasal cavity or nasopharynx include infections, chronic rhinosinusitis, foreign bodies, tooth root disease, neoplasia, inflammatory polyps, nasopharyngeal stenosis, trauma, and cleft palate1–3 (TABLE 1). In addition, vomiting or regurgitation can lead to sneezing or nasal discharge if gastrointestinal contents are aspirated into the nose via the nasopharynx. Serous nasal discharge is characteristic of most acute diseases of the nasal cavity and may precede mucopurulent nasal discharge. Chronic serous nasal discharge is most commonly associated with viral and allergic etiologies. Mucopurulent nasal discharge (FIGURE 1) is a sign of inflammation and occurs in association with fungal disease, primary bacterial disease, or overgrowth of normal bacterial flora secondary to chronic nasal disease (neoplasia, chronic rhinosinusitis, oronasal fistula, foreign body, inflammatory polyp, or viral disease). Epistaxis alone is most common with trauma, acute foreign body, hypertension, or coagulopathy. Epistaxis that develops in conjunction with, or after, mucopurulent dis-

mon in cats. Common diagnostic differentials include viral, bacterial, and fungal infections; chronic rhinosinusitis; foreign bodies; tooth root disease; neoplasia; inflammatory polyps; nasopharyngeal stenosis; and trauma. A complete diagnostic workup is important to determine the etiology so that the treatment regimen can be appropriately directed and maximal response to therapy obtained.

C

linical signs of upper respiratory disease, including sneezing and nasal discharge, are common in cats. Some diseases are commonly associated with sneezing, and others are more commonly associated with sonorous breathing with or without gagging; coughing can sometimes be present, as well as epiphora, halitosis, and dysphagia.1–3 Sneezing is a superficial reflex that originates in the mucous membranes lining the nasal cavity and is easily induced by chemical or mechanical stimuli. During a sneeze, air is forcefully expulsed through the respiratory passageways at a great velocity to clear them. Nasal discharge can be serous, mucopurulent, or hemorrhagic.

Etiologies and Clinical Signs

At a Glance Etiologies and Clinical Signs Page 554

General Diagnostic Considerations Page 557

MORE ON THE WEB a Dr. Quimby discloses that she has received study funding from Bayer HealthCare Animal Health.

554

Compendium | December 2009 | Vetlearn.com

Coming Soon: A companion article on diseasespecific tests and therapies will be published in January 2010.


In association with

AMERICAN ASSOCIATION OF

FELINE PRACTITIONERS

About AAFP The American Association of Feline Practitioners improves the health and well-being of cats by supporting high standards of practice, continuing education, and scientific investigation. Feline practitioners are veterinary professionals who belong to this association because they are “passionate about the care of cats”!

FIGURE 1

American Association of Feline Practitioners 203 Towne Centre Drive Hillsborough, NJ 08844-4693 phone: 800-874-0498 phone: 908-359-9351 fax: 908-292-1188

Clinical appearance of chronic mucopurulent nasal discharge.

e-mail: info@catvets.com

charge is most common with fungal disease, neoplasia, oronasal fistula, and, occasionally, chronic foreign bodies. Vasculitis is a rare cause of nasal discharge in cats; it is a more common cause in dogs with diseases such as ehrlichiosis and bartonellosis. Unilateral nasal discharge is more likely with foreign bodies, oronasal fistula, and neoplasia, although discharge can become bilateral as neoplasia progresses. Bilateral discharge is a nonspecific sign that can have almost any etiology.1 Infectious agents are commonly associated with sneezing or nasal discharge in cats. The primary viral agents are feline herpesvirus 1 (FHV-1; FIGURE 2) and feline calicivirus (FCV).4–8 Bacterial agents that have been described as primary respiratory patho-

gens in cats include Bordetella bronchiseptica, Chlamydophila felis, Streptococcus canis, and Mycoplasma spp; Corynebacterium spp, Escherichia coli, Pasteurella multocida, Pseudomonas aeruginosa, Streptococcus viridans, and Staphylococcus intermedius are also commonly detected but are generally thought to be secondary invaders.7–16 Cryptococcus neoformans and Aspergillus spp are the most common fungal causes of upper respiratory disease in cats.17,18

Media contact: Valerie Creighton, DVM, DABVP

General Diagnostic Considerations Signalment and lifestyle often help refine the differential diagnosis and direct a diagnostic workup. Brachycephalic breeds may be predisposed to nasal disorders due to physical

TABLE 1

Clinical Manifestations of Upper Respiratory Diseases in Cats Disease

Signalment and History

Sneezing

Nasal Discharge

Respiratory Noise

Acute viral infection

Young to any age; acute

Often

Serous to mucopurulent

Sometimes

Bacterial infection

Any age; chronic

Sometimes

Mucopurulent

Sometimes

Fungal infection

Any age; chronic

Sometimes

Mucopurulent to hemorrhagic

Sometimes

Nasopharyngeal polyp

Young; chronic

Sometimes

Mucopurulent

Often

Chronic rhinosinusitis

Any age; chronic

Often

Mucopurulent to hemorrhagic

Sometimes

Older; chronic

Sometimes

Mucopurulent to hemorrhagic

Often

Any age; chronic

Rarely

Uncommon

Often

Any age; acute

Often

Variable

Rarely

Neoplasia Nasopharyngeal stenosis Foreign body

Vetlearn.com | December 2009 | Compendium: Continuing Education for Veterinarians®

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Connecting better with your clients...

conformation.19 Neoplasia is more likely in older cats,1 and nasopharyngeal polyps are more common in younger cats.20 Outdoor cats are more likely to acquire foreign bodies, sustain trauma, or develop infectious etiologies.1 Cats in crowded housing conditions such as catteries, shelters, or multicat households are more likely to develop acute or chronic viral or bacterial rhinitis.6 Obtaining a complete history is important for determining the duration of the clinical signs. Acute onset of clinical signs is common with viral agents, foreign bodies, and trauma. The diagnostic workup of sneezing and nasal discharge is commonly completed in three phases.

Phase 1

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Most cats with acute disease are evaluated with noninvasive tests and therapeutic trials. A complete physical examination with careful attention to the head and neck, including ocular retropulsion, should be performed.An otic examination should be completed to evaluate the tympanum for bulging or discoloration; these changes commonly occur with nasopharyngeal polyps. Deformation of the nose or face, exophthalmia, or pain on palpation of the nasal or facial bones is most consistent with fungal disease or neoplasia.1 An oral examination should be performed to assess for dental disease that could be causing an oronasal fistula, gingivostomatitis that could be consistent with FHV-1 or FCV infection, and defects in the hard or soft palate. External ocular examination may reveal conjunctivitis, which can be a sign of infection with FHV1, FCV, Mycoplasma spp, or C. felis. A fundic examination is performed to evaluate for lesions consistent with lymphoma or C. neoformans infection. A cold microscope slide placed in front of the nose can aid in assessing airflow and determining whether obstruction is unilateral or bilateral, although these findings should not limit diagnostic investigation to one side of the nose. Although identification of fungal organisms is uncommon, cytology should be performed on samples of mucoid to mucopurulent nasal discharge to evaluate for the presence of C. neoformans or hyphae consistent with Asper-gillus or Penicillium spp. Neutrophils and bacteria are commonly detected if mucopurulent disease is present, but their presence does not prove primary bacterial disease. Likewise, hyphae do not confirm primary fungal disease because they may represent contamination or infection secondary to another underlying cause. Secondary infections result in the same types of discharge as primary infections. If lymph nodes draining the head are enlarged, they should be aspirated to evaluate for the presence of lymphoma, metastatic neoplasia, and fungal agents.

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Compendium | December 2009 | Vetlearn.com


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FIGURE 2

Clinical appearance of a kitten with herpesvirus infection.

QuickNotes Signs of nasal disease are nonspecific, and a diagnostic workup is necessary to pinpoint the etiology and direct therapy.

560

Bacterial culture and antimicrobial susceptibility testing of nasal discharge samples are generally not recommended because the results typically yield normal intranasal bacterial flora and are, therefore, difficult to interpret.21 However, in respiratory outbreaks in catteries, pet stores, shelters, or multiple cat households, culture may be indicated to determine whether pathogenic B. bronchiseptica is present. Molecular diagnostic assays are available for many respiratory agents, including FHV-1, FCV, C. felis, Mycoplasma spp, and B. bronchiseptica. However, cats can be asymptomatic carriers of these agents, and the FHV-1, FCV, and C. felis assays also amplify vaccine strains; therefore, positive results do not prove a disease association, especially for FHV-1 and FCV, which may have relatively high prevalences in the healthy cat population.4,5,22 A recent study23 failed to link infection with Bartonella spp to rhinitis in cats, so the question of whether to perform serology, culture, or polymerase chain reaction (PCR) assays for Bartonella spp in cats with rhinitis is controversial. If a clinician chooses to test for evidence of Bartonella infection, samples should be evaluated by PCR or culture in addition to serology, as serology alone has been shown to produce false-negative results in up to 15% of

infected cats. In addition, only approximately 40% of seropositive cats are currently infected; therefore, a positive serologic test result does not prove bartonellosis.24 A complete blood cell count (CBC), a serum biochemical panel, and urinalysis are recommended to rule out other systemic disease processes in cats with chronic disease. In general, CBC results are of low yield but may reveal eosinophilia in some cats with fungal or allergic disease, thrombocytopenia in some cats with epistaxis, or other cytopenias that might accompany FeLV or FIV infection. FeLV and FIV do not cause sneezing and nasal discharge primarily, but they have been associated with lymphoma and may induce immunodeficiency that predisposes to other infections; therefore, testing for these agents is indicated. A Cryptococcus antigen test is also recommended as a preliminary test for cats with chronic nasal discharge, particularly those with nasal deformation, lymphadenopathy, or retinal lesions.25 Although thoracic radiographs are generally normal, they are indicated to rule out pulmonary involvement of fungal disease and metastatic neoplasia. In cats with epistaxis, a blood pressure reading, coagulation profile, and buccal mucosal bleeding test are recommended, and thromboelastography may also be useful. Therapeutic trials are commonly attempted in cats with mild disease and usually consist of antibiotics, antiviral drugs, immunomodulators, or antihistamines.

Phase 2 If the physical examination indicates the need for further diagnostic workup, a definitive diagnosis is not made during Phase 1, or if routine therapeutic trials fail, more aggressive diagnostic testing (requiring general anesthesia) should be pursued. Phase 2 diagnostics usually consist of pharyngeal examination, computed tomography (CT) or skull and dental radiography, rhinoscopy, bacterial and fungal cultures, and biopsy for histology. In anticipation of the potential for biopsy, a platelet estimate and an activated clotting time or other coagulation function test should be conducted before anesthesia is induced.

Compendium: Continuing Education for Veterinarians® | December 2009 | Vetlearn.com


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FIGURE 3 Computed tomography (CT) images of two cats presented for upper respiratory signs.

CT appearance of mild chronic rhinitis.

QuickNotes Although computed tomography is more expensive, it has many advantages over skull radiography.

General anesthesia is induced by administering approximately one-third of an induction dose of propofol, a short-acting thiobarbiturate, or ketamine combined with diazepam. The arytenoid cartilages are examined to make sure both are abducting normally on inspiration. Oropharyngeal examination is performed to evaluate thoroughly for masses, FIGURE 4

Rhinoscopic image from a cat with chronic rhinitis. The mucosa is irregular, erythematous, and swollen, and there is loss of turbinate structure.

562

CT appearance of a nasal tumor. A mass effect is noted in the nasal cavity. The white arrow indicates bony lysis and loss of the nasal septum; the red arrow indicates complete obstruction of the nasopharyngeal canal by the mass.

foreign bodies, or palate defects. A spay hook and dental mirror can be used to help manipulate the soft palate to allow visualization of the nasopharynx to check for polyps, other masses, foreign material, or nasopharyngeal stenosis. A thorough dental examination should be performed and all teeth probed for evidence of an oronasal ďŹ stula. If a deďŹ nitive diagnosis is not made, CT or nasal, sinus, and dental radiography is conducted. Radiography must be performed with the patient under anesthesia for accurate positioning and include lateral, ventrodorsal, intraoral, and open-mouth bullae views. Nasal imaging can reveal increased density in the nasal cavity or bony lysis that could be consistent with a mass, turbinate destruction consistent with chronic rhinosinusitis or fungal disease, radiopaque foreign objects, or tooth-root abscessation.26,27 Although more expensive, CT has the advantages of allowing better visualization of the sinuses and tympanic bullae, better assessment of bony lysis, and assessment of the cribriform plate and brain to evaluate the extent of a lesion.28 It is also quicker to conduct than

Compendium: Continuing Education for VeterinariansÂŽ | December 2009 | Vetlearn.com


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QuickNotes The gross appearance of the nasal mucosa on rhinoscopy does not always correlate with the histopathologic diagnosis, so biopsy samples should always be obtained.

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a full series of skull radiographs and allows biopsy samples can be submitted for bacterial for radiotherapy treatment planning, if indi- and fungal cultures.30 cated. CT is the preferred imaging modality, especially if a mass is suspected (FIGURE 3). Phase 3 Images should be obtained before rhinos- Exploratory rhinotomy allows direct visualcopy and biopsy are performed to avoid ization of the nasal cavity to identify foreign hemorrhage obscuring details in the nasal objects, masses, or fungal plaques and is occasionally conducted in dogs to aid in the diagpassages. Depending on the radiography or CT find- nostic workup and in the treatment of some ings, the nasopharynx is examined with a flex- diseases. However, it is rarely conducted in cats, ible rhinoscope, and rigid rhinoscopy of the except for cases requiring removal of chronianterior nasal cavity is conducted. Rhinoscopy cally embedded foreign bodies or cases of allows direct visualization of the nasal cav- Aspergillus or other sinus infections that were ity, detection and removal of foreign objects, refractory to treatment or for which endoscopic detection and debridement of fungal plaques, debridement was insufficient. Nasal cryptococand assessment for inflammation, turbinate cosis rarely requires debulking in cats. In gendestruction, and masses (FIGURE 4). However, eral, there is no added benefit of debulking if a mass is present, rhinoscopy does not allow nasal tumors before chemotherapy (for lymassessment of the extent of bony lysis, mak- phoma) or radiation therapy. While removing ing additional imaging important. In addition, turbinate tissue can increase airflow through the gross appearance of the nasal mucosa on the nasal cavities, bacterial osteomyelitis and rhinoscopy does not always correlate with the some nasal discharge often persist, so this prohistopathologic diagnosis, so biopsy samples cedure is generally not recommended for cats should always be obtained.29 with chronic inflammatory rhinitis. If no foreign material is visualized on rhinoscopy, the nasal cavity is flushed with Conclusion sterile saline to evaluate for the presence Clinical signs of upper respiratory disease are of hidden material. The cuff of the endotra- common in cats. Viral upper respiratory infeccheal tube should be checked for full infla- tions, trauma, and foreign bodies are perhaps tion before nasal lavage is performed with the most common diagnostic differentials saline administered under pressure. In cats, when the onset of clinical signs is acute, but we recommend lavaging from the anterior when the signs are more chronic, bacterial nares caudally. Gauze should be placed in the and fungal infections, chronic rhinosinusitis, oropharyngeal area, and a 20-, 35-, or 60-mL chronically embedded foreign bodies, tooth syringe can be used to forcefully flush saline root disease, neoplasia, inflammatory polyps, through the nose while the nares are pinched and nasopharyngeal stenosis must be considoff to create pressure. Material flushed from ered. A diagnostic workup can be performed in the nose (or oropharynx) should be caught on several stages. A minimum database, cytology, the gauze and examined for foreign bodies. If infectious disease assays, diagnostic imaging, no foreign material is found, biopsy samples and biopsy may be required to determine the are taken using a bone curette or the largest etiology so that the treatment regimen can be biopsy instrument that can be passed through appropriately directed and maximal response the nares. Most rigid endoscopes are too large to therapy obtained. for use with the biopsy sleeve in many cats; however, a gastroscopic biopsy instrument ON THE can often be passed next to the camera of a The references for this WEB small rigid scope to perform a directed biopsy. article are available on Alternatively, the biopsy site can be chosen Vetlearn.com. based on the results of diagnostic imaging or rhinoscopy. If indicated, flushed material or

Compendium: Continuing Education for Veterinarians® | December 2009 | Vetlearn.com


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